Projectile



I March 11,1941. J. s. HATCHER :rm.

Inventors Julian 5 Hat|:her John E-Gray BMW M Attorney Patented Mar. 11,1941 PRoJEoTiLn Julian Hatcher, AnnapoliavMd and John 1C.

Y Gray, Washington, D. O.

I iptiicaasoaoba 31, 1939, Serial No. 302,130

1 ilOlaims. (01.102-26) (Granted under the act of March a, .1883, as

amended April 30, 1928; 370

The invention described herein may be manufactured and used by or forthe Government for governmental purposes, without the payment to us ofany royalty thereon. l

l This'invention relates to a projectile, and more especially to highvelocity long'range bullets.

The main objects of the invention are the production of a projectilewhich will offercomparatively small frictional resistance to startingmotionl and travel through a gun barrel thereby permitting the use oflarger propellent charges without dangerous increase'in' the gaspressure within the barrel with consequent higher velocity of projectiletravel, and the formation of such projectile in a manner to permitproper air flow thereby to the end that proper exterior ballisticcharacteristics will be maintained.

The foregoing objects are attained broadly by decreasing the area ofcontact of the projectile with'the lands and grooves of the gun barrel,and by directing the air stream by the bullet in a manner to avoidcontact thereof with projecting air resisting surfaces of theprojectile.

More specifically the projectile includes a body whose diameter is nogreater than the diameter across the lands of the barrel and it isprovided with bands to take the rifling, the bands so situated as toproperly balance the projectile in its travel through the barrel andseal the bore in such a manner that the maximum efiect of the propellentpowder gas will be obtained with a minimum erosion. The head of theprojectile has an ogive selected to cause the air stream to be defiectedbeyond the external diameter of the bands.

The specific nature of the invention as well as other objects andadvantages thereof will clear- 1y appear from a description of apreferred embodiment as shown in the accompanying drawing in which:

Fig. 1 is a longitudinal sectional view of the improved projectile.

Fig. 2 is a longitudinal sectional view of another form of projectile.

Referring to the drawing by characters of reference:

The projectile comprises a cylindrical body 5, a base 6 which is hereinshown as cylindrical but which may be boat-tailed, an ogival head I, andfront and rear hands respectively 8 and 9 which occupy positions at theends of the body. The projectile has a length which is approximatelyfour and one-quarter times the maximum diameter which is at the bands 8and 9.

The body 5 is cylindrical and has a diameter less than one caliber sothat it will be clear of the lands of the rifiing. The length of thebody is substantially the same as its diameter.

The bands Band 9 which provide engagement with the rifling for thepurpose of rotating and centering the projectile have a diameter sub- 5stantially equal to the diameter between the bottoms of opposite groovesof the rifling. The width of the front band 8 should be .04" to .05 fora .30 caliber projectile while'the Width of the rear band isapproximately .03". The positioning of the 10 rear band slightly morethan one-quarter caliber from the rearend of the base produces theoptimum form for reduction of air resistance. If the band is placedcloser than one-quarter caliber to the rear end serious air resistancewill be encountered and the stability of the projectile in flight willbe impaired.

The rear face of the projectile is recessed in the form of a cone or cupill the greatest depth of which lies on the longitudinal axis of thebullet and is approximately one-quarter of a caliber in depth. Thisprovision reduces the drag of the air on the base of the projectileduring flight.

The head I is from two and one-half to three calibers in length and thecurve of the ogive is of from seven to nine calibers radius. The curvewhen projected is tangent to the periphery of the band 8 and is recedingfrom the longitudinal axis of the projectile at the rear of the head andadjacent the front band 8 so that the air stream passing over the ogivalhead will clear the front band and thereby reduce air resistance.

Referring to Fig. 1, the ogive terminates short of the front band 8 toprovide a cylindrical portion II at the rear part of the head which hasthe same diameter as the body 5.

In the form shown in Fig. 2 the ogival head I2 merges with the frontband portion [3.

The rifle in which these bullets are to be used may be equipped with anystandard form of rifling it being necessary only to assure suflicientbearing surface on the driving edge of the lands to prevent stripping orshearing of the bands, which may be accomplished by deeper rifiing or anincrease in the number of lands. The rifiing may, if desired becontinued through only a portion of the barrel sufiicient to give thebullet a proper spin about its longitudinal axis and the remainder ofthe barrel toward the muzzle may be smooth.

Experiments with these bullets show an extremely high velocity withproper ballistic characteristics, and further indicate that the recessin the base of the bullet reduces the drag on the bullet at these highvelocities.

While the bullets herein shown are represented as solid, it is to beunderstood that the same may be jacketed, and have a metal core in thewell known manner, the jacket in such instance being somewhat heavierthan the usual jacket at present in use.

We claim:

1. A projectile including a body portion substantially one caliber inlength and having a diameter less than one caliber, band portions at thefront and rear of the body portion and having a diameter greater thanone caliber, an ogival head portion forwardly of the front band portion,said head portion having a length of two and one-half to three calibersand an ogive of from seven to nine calibers radius the projection ofwhich is tangent to the periphery of the front band portion.

2. A projectile including a body portion substantially one caliber inlength and having a diameter less than one caliber, band portions at thefront and rear of the body portion and having a diameter greater thanone caliber, an ogival head portion forwardly of the front band portion,said head portion having a length of two and one-half to three calibersand an ogive of from seven to nine calibers radius tangent to theperiphery of the front band portion.

3. A projectile including a body, a narrow rotating band at the forwardend of the body, and an ogival head with its rear terminus forward ofthe band, the curvature of the ogive when projected being tangent to theperiphery of the band.

4. A projectile including a body, a rotating band at the forward end ofthe body, and an ogival head of from seven to nine calibers radius, thecurvature of the ogive being tangent to the periphery of the band.

5. A projectile including a body, a rotating band at the forward end ofthe body, an ogival head terminating short of the band, the curvature ofthe ogive when projected being tangent to the periphery of the band, andthe portion between the band and rear terminus of the ogive having adiameter substantially the same as the diameter of the body.

6. A projectile including a body portion and an ogival head portion offrom seven to nine calibers radius, the curve of the ogive tangent to acylinder having. a diameter greater than the diameter of the bodywhereby the rear portion of the head constitutes a rotating band, and arifling band on the rear portion of the body portion.

'7. A projectile including a body substantially one caliber in lengthand having a diameter less than one caliber, a base in rear of the body,a band portion between the base and body and substantially one-quarterof a caliber from the rear end of the base, a band portion at theforward end of the body, and an ogival head having a length between twoand one-half and three calibers and a curvature based on the forwardband portion.

JULIAN S. HATCHER. JOHN C. GRAY.

